Inter-laboratory comparison of triple point of water (TPW) cells

Project Description

Comparison of TPW realisations through a circulating TPW cell according to ITS-90.

Progress Report 2020-06-04

The comparison measurements were completed – including the final TPW measurements by the pilot lab - by all the participants and the reports were sent to the pilot laboratory.  The Draft A report of the comparison has already been written and will be sent to participant laboratories by the second half of June 2020.
The Draft B report of the comparison including the link to the CCT-K7 comparison results is expected to be published on September 2020. Final report is planned to be published before the end of this year.

Progress Report 2019-03-06

In addition to last year's report , it should be mentioned that only IMBiH accepted to carry out the measurements with the TPW cell which had been circulated formerly in the second loop. Therefore the TPW cell was sent only to IMBiH and received back after the measurements were completed. Currently, the results of IMBiH are expected while the final comparison measurements are being carried out at TUBITAK UME. After all results have been obtained, the draft A report of the comparison will be published. 

Progress Report 2018-03-16

The measurements in the first loop, including EURAMET countries were completed. But unfortunately the circulating cell was broken during the transportation from last participant to UME. When we finished the evaluation of comparison results received from all participants of EURAMET loop, we noticed that, the temperature of  TPW cell seems to  shift eventually meaning that temperature deviation from the reference cell increased more and more as comparison proceeded.  Finally, it was observed that the presented results  by participant labs were significantly different from the reference cell which will link our results to CCT K7 reference value. Another part of the problem is missing of final TPW measurements at UME.  No problem observed with TPW cell of the other loop therefore I proposed to circulate this TPW cell in EURAMET loop and repeat the measurements. IMBiH agreed on this proposal. I'm waiting for other laboratories' decision. EMI and JNMI completed the measurments and sent the comparison reports.  Currently, SASO is carrying out comparison measurements.

Progress Report 2017-04-07

This comparison was initiated as EURAMET 1357. New participants from EURAMET and GULFMET were included in the comparison after having approvals of each partipting laboratory. Then it was registered as Key Comparison with the name EURAMET.T-K7-4 in KCDB. The protocol was approved by CCT WG-KC. An additional loop comprising GULFMET countries (EMI, SASO, JNMI) was introduced in the comparison. The measurements in the first loop, including EURAMET countries were completed. But unfortunately the circulating cell was broken during the transportation from last participant to UME. This unexpected situation would bring some complications such as the missing of final TPW measurements at UME . In the second loop EMI completed the measurements and transferred the cell to SASO. Currently SASO is performing measurements. Up to now, only one laboratory reported the comparison results.  

Progress Report 2016-01-28

The protocol has been revised according to the participants' suggestions. The pilot lab UME, IMBiH and MBM completed the measurements. The circulating TPW cell is at BoM for the time being.

Thermometry (T)
Ali Uytun, UME (Turkey)
Phone: +90 262 6795000-3403
Coordinating Institute
UME (Turkey)
Participating Partners
IMBiH (Bosnia and Herzegovina)
Further Partners
Emirates Metrology Institute (United Arabic Emirates)
Saudi Standards, Metrology and Quality Organization (Saudi Arabia)
Jordan National Metrology Institute (Jordan)